BuilderStructure.cs

//-------------------------------------------------------------------------------------
//	BuilderStructure.cs
//-------------------------------------------------------------------------------------

using UnityEngine;
using System.Collections;
using System.Collections.Generic;

public class BuilderStructure : MonoBehaviour
{
    void Start()
    {
        // Create director and builders
        Director director = new Director();

        Builder b1 = new ConcreteBuilder1();
        Builder b2 = new ConcreteBuilder2();

        // Construct two products
        director.Construct(b1);
        Product p1 = b1.GetResult();
        p1.Show();

        director.Construct(b2);
        Product p2 = b2.GetResult();
        p2.Show();
    }
}

class Director
{
    // Builder uses a complex series of steps
    public void Construct(Builder builder)
    {
        builder.BuildPartA();
        builder.BuildPartB();
    }
}

abstract class Builder
{
    public abstract void BuildPartA();
    public abstract void BuildPartB();
    public abstract Product GetResult();
}

class ConcreteBuilder1 : Builder
{
    private Product _product = new Product();

    public override void BuildPartA()
    {
        _product.Add("PartA");
    }

    public override void BuildPartB()
    {
        _product.Add("PartB");
    }

    public override Product GetResult()
    {
        return _product;
    }
}

class ConcreteBuilder2 : Builder
{
    private Product _product = new Product();

    public override void BuildPartA()
    {
        _product.Add("PartX");
    }

    public override void BuildPartB()
    {
        _product.Add("PartY");
    }

    public override Product GetResult()
    {
        return _product;
    }
}

class Product
{
    private List<string> _parts = new List<string>();

    public void Add(string part)
    {
        _parts.Add(part);
    }

    public void Show()
    {
        Debug.Log("\nProduct Parts -------");
        foreach (string part in _parts)
        {
            Debug.Log(part);
        }
    }
}